TROJ_DASMIN.A

Malware type: Trojan

Aliases: Trojan-Clicker.Win32.Sjfs (Kaspersky), AdClicker-H (McAfee), Trojan Horse (Symantec), TR/Click.Sjfs.4 (Avira), Troj/AdClick-I (Sophos),

In the wild: No

Destructive: No

Language: English

Platform: Windows

Encrypted: Yes

Overall risk rating:

Description: 
This Trojan program changes current Internet Explorer homepage and search page with a blank page. It also replaces the host table with an empty Italian-version host table.

For additional information about this threat, see:

Description created: Oct. 11, 2002 6:10:35 PM GMT -0800
Description updated: Oct. 11, 2002 7:16:40 PM GMT -0800


TECHNICAL DETAILS


Size of malware: 59,904 Bytes

Initial samples received on: Oct 11, 2002

Payload 1: Modifies Internet Explorer Homepage and Search page

Trigger condition 1: Upon execution

Details:
Upon execution, this Trojan copies itself as JDBGMRG.EXE in the Windows system directory. It then modifies the registry to enable its automatic execution every Windows startup. The modified registry appears as follows:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run,
MSAdmin = %System%\jdbgmrg.exe

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\
CurrentVersion\RunServices,
MSAdmin = %System%\jdbgmrg.exe

(%System% refers to the Windows system directory, which is usually C:\Windows\System or C:\WinNT\System32.)

This Trojan then proceeds to change current Internet Explorer homepage and search page with ABOUT:BLANK, which gives a blank page. It does this by modifying the registry as follows:

HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main,
Start Page = about:blank
Search Page = about:blank

It also replaces the host table of the infected system with an empty Italian-version host table. The host table is pointed to by this path:

%Windows%\System32\driver\etc\hosts

(%Windows% refers to the Windows directory, which is usually C:\Windows or C:\WinNT.)

This Trojan also accesses this Web site, possibly to earn points in a Web site referral system:

http://www.k<BLOCKED>count.net/image.php


SOLUTION


Minimum scan engine version needed: 6.810

Pattern file needed: 1.366.26

Pattern release date: Oct 11, 2002


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

AUTOMATIC REMOVAL INSTRUCTIONS

To automatically remove this malware from your system, please use Trend Micro Damage Cleanup Engine and Template.

MANUAL REMOVAL INSTRUCTIONS

Identifying the Malware Program

Before proceeding to remove this malware, first identify the malware program.

Scan your system with Trend Micro antivirus and NOTE all files detected as TROJ_DASMIN.A. To do this, Trend Micro customers must download the latest pattern file and scan their system. Other Internet users can use HouseCall, Trend Micro's free online virus scanner.

Terminating the Malware Program

This procedure terminates the running malware process from memory. You will need the name(s) of the file(s) detected earlier as TROJ_DASMIN.A.

  1. Open Windows Task Manager.
    On Windows 9x/ME systems, press
    CTRL%20ALT%20DELETE
    On Windows NT/2000/XP systems, press
    CTRL%20SHIFT%20ESC, and click the Processes tab.
  2. In the list of running programs*, locate the malware file or files detected earlier.
  3. Select one of the detected files, then press either the End Task or the End Process button, depending on the version of Windows on your system.
  4. Do the same for all detected malware files in the list of running processes.
  5. To check if the malware process has been terminated, close Task Manager, and then open it again.
  6. Close Task Manager.

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing during startup.

  1. Open Registry Editor. To do this, click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>Software>Microsoft>
    Windows>CurrentVersion>Run
  3. In the right panel, locate and delete the entry:
    MSAdmin
  4. In the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>RunServices
  5. In the right panel, locate and delete the entry or entries:
    MSAdmin
  6. Close Registry Editor.

Resetting Internet Explorer Homepage and Search Page

This procedure restores the Internet Explorer home page and search page to the default settings.

  1. Close all Internet Explorer windows.
  2. Open Control Panel. Click Start>Settings>Control Panel
  3. Double-click the Internet Options icon.
  4. In the Internet Properties window, click the Programs tab.
  5. Click the �Reset Web Settings�� button.
  6. Select �Also reset my home page.� Click Yes.
  7. Click OK.

Running Trend Micro Antivirus

Scan your system with Trend Micro antivirus and delete all files detected as TROJ_DASMIN.A. To do this, Trend Micro customers must download the latest pattern file and scan their system. Other Internet users can use HouseCall, Trend Micro's free online virus scanner.


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